Fig. 7

Synthesis of nanopariticles for drug delivery. a Nanoparticles encapsulating therapeutic agent(s) were synthesized using a double-emulsion water-in-oil-in-water method. The inner water phase containing anti-miR21 inhibitor and CG-CO₂ were encapsulated in the core, and hydrophobic WIP1 inhibitor (GSK2830371) together with PLGA and DPPC dissolved in oil phase was used to form the shell structure. b TEM images of nanoparticles in pH 7.4, 6.0, and 5.0, respectively. Nanoparticles maintained spherical morphology with clear core-shell structure in pH 7.4, and enlarged and broken under low pH (pH 6.0 and pH 5.0) indicated the pH-responsive behavior. c Electrophoretic stability assay of in-MW@NP and free anti-miR21 inhibitor at different incubation time points in serum at 37 °C. The observable signal of in-MW@NP indicated that the nanoparticle encapsulation could protect anti-miR21 inhibitor from degradation in serum up to 36 h. d Typical confocal imaging of cells incubated with Dex-Rho@NP for 1–6 h. The change of the fluorescence overlap of Dex-Rho (red) and Lysotracker (green) shows the CO₂-associated pH-responsive endo/lysosomal escape in HER18R cells. Cell nuclei were stained with DAPI (blue), endo/lysosomal vesicles were stained with LysoTracker Green, and DIC represented differential interference contrast. Data are representative of 3 independent experiments